A method and system for developing a start-stop plan for a combined heat and power unit

Abstract

A method and system for developing a start-stop plan of a cogeneration unit, comprising: when there is wind curtailment: calculating the maximum heat supply of the cogeneration unit based on the power supply condition of the cogeneration unit; determining the heat supply that can be provided by the cogeneration unit based on the maximum heat supply; and determining the start-stop plan of the cogeneration unit based on the heat supply that can be provided and the obtained heat load prediction curve. The present application is a new mode for developing a unit combination to improve the wind power consumption capacity, meets the actual heat and power joint dispatching demand, further improves the space for wind power consumption under the premise of guaranteeing the heat supply demand, fully utilizes the heat load prediction, and further improves the utilization rate of wind power.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of power systems, in particular to a cogeneration unit start-stop plan making method and system. BACKGROUND

[0002] At present, the installed capacity of new energy is the largest in the world. However, due to factors such as power supply structure, resource distribution and power grid structure, the problem of new energy consumption is becoming more and more prominent year by year. Wind power has the characteristics of randomness, volatility and intermittency, and the wind power consumption is directly affected by the regulation capacity of conventional power sources. When the fluctuation range of wind power output exceeds the regulation capacity of the power grid, wind power will be abandoned. In some areas, the proportion of thermal power units, especially cogeneration units, is high. In winter, the city heat supply network mainly supplies heat through large-scale thermal power units. In the "heat determines electricity" operation mode, the peak shaving capacity of cogeneration units is significantly reduced. In order to ensure the active balance of heat supply and power grid during the low load period, a large amount of wind power is abandoned, which seriously affects the acceptance of wind power. In the traditional power unit combination, in order to fully ensure the heating of residents, the cogeneration unit needs to strictly formulate the start-stop plan and the minimum operation output of the cogeneration unit according to the regulations. The result of this cogeneration unit start-stop plan making method is generally conservative, which will lead to excessive start-up units and minimum operation output during the winter heating period, reducing the wind power consumption space and being not conducive to the improvement of wind power utilization rate. SUMMARY

[0003] In order to solve the above-mentioned problems existing in the prior art, the present application provides a cogeneration unit start-stop plan making method and system.

[0004] The technical scheme provided by the present application is:

[0005] A cogeneration unit start-stop plan making method, the method comprises:

[0006] When there is wind power abandonment, the maximum heat supply of the cogeneration unit is calculated based on the power supply condition of the cogeneration unit;

[0007] The heat supply capacity provided by the cogeneration unit is determined based on the maximum heat supply;

[0008] The start-stop plan of the cogeneration unit is determined based on the heat supply capacity provided by the cogeneration unit and the obtained heat load prediction curve.

[0009] Preferably, the heat supply capacity provided by the cogeneration unit is determined based on the maximum heat supply, comprising:

[0010] The range of safety margin is determined according to the power of the cogeneration unit;

[0011] The range of heat supply capacity provided by the cogeneration unit is determined according to the range of safety margin and the maximum heat supply;

[0012] The safety margin is 10%-30%.

[0013] Preferably, the calculation formula of the heat supply of the cogeneration unit is as follows:

[0014]

[0015] P = Pmax- K / c 可 Pmax is the maximum heat supply of each cogeneration unit; H is the heat load prediction curve; and η is the safety margin. h,i,max Pmax is the maximum heat supply of each cogeneration unit; H is the heat load prediction curve; and η is the safety margin. L,t Pmax is the maximum heat supply of each cogeneration unit; H is the heat load prediction curve; and η is the safety margin.

[0016] Preferably, the calculation formula of the maximum heat supply of the cogeneration unit is as follows:

[0017] Pmax= Pmax- K / c b,h,max Pmax= Pmax- K / c b,e,max K b K m

[0018] Pmax= Pmax- K / c c,h,max Pmax= Pmax- K / c c,e,max K c K m K v1

[0019] Pmax= Pmax- K / c b,h,max Pmax= Pmax- K / c b,e,max Pmax= Pmax- K / c c,h,max Pmax= Pmax- K / c c,e,max Pmax= Pmax- K / c b K c K m K v1

[0020] Preferably, the determination of the start-stop plan of the cogeneration unit based on the heat supply and the obtained heat load prediction curve comprises:

[0021] calculating the minimum number of running cogeneration units based on the heat supply of the cogeneration unit and the obtained heat load prediction curve;

[0022] comparing the current number of running cogeneration units with the minimum number of running cogeneration units to determine the number of cogeneration units that need to be stopped or started;

[0023] ​​Formulate a start-stop plan of the cogeneration unit based on the number of units that need to be stopped or started.

[0024] Preferably, the calculation formula of the minimum number of units is as follows:

[0025]

[0026] wherein I is the number of units of the cogeneration unit; η is the safety margin; P h,i,max is the maximum heat supply of each cogeneration unit; P c,e,max is the maximum power supply of the cogeneration unit in the condensing mode; K b ,K c is the coupling constant; c m is the heat-power coupling coefficient of the back pressure mode cogeneration unit; c v1 is the heat-power coupling coefficient of the maximum power supply mode of the extraction turbine unit; H L,t is the heat load prediction curve; I b is the number of units of the back pressure cogeneration unit; I c is the number of units of the extraction turbine cogeneration unit.

[0027] Preferably, the formulating the start-stop plan of the cogeneration unit further comprises:

[0028] if the start-stop plan meets the heat supply demand, the start-stop plan is sent to the cogeneration plant for execution;

[0029] otherwise, the abandoned wind power is recalculated, and the maximum heat supply of the cogeneration unit is calculated based on the power supply mode of the cogeneration unit;

[0030] the heat supply provided by the cogeneration unit is determined based on the maximum heat supply;

[0031] the start-stop plan of the cogeneration unit is determined based on the heat supply provided and the obtained heat load prediction curve;

[0032] until the start-stop plan meets the heat supply demand, and the start-stop plan that meets the heat supply demand is sent to the cogeneration plant for execution.

[0033] Preferably, the calculation of the abandoned wind power comprises:

[0034] obtaining the heat load prediction curve and the wind power;

[0035] obtaining the minimum technical output of the whole network based on the start-up plan of the conventional generator unit;

[0036] obtaining the generation load of the whole network in the prediction period based on the heat load prediction curve and the transaction of the external tie line;

[0037] Calculate the difference between the total network power generation load and the total network minimum technical output to obtain a wind power accommodation space;

[0038] Calculate the wind curtailment based on the wind power and the wind power accommodation space.

[0039] A cogeneration unit start-stop plan making system, the system comprises:

[0040] A first calculation module: for when there is wind curtailment: calculating the maximum heat supply of the cogeneration unit based on the power supply power condition of the cogeneration unit;

[0041] A second calculation module: for determining the heat supply that the cogeneration unit can provide based on the maximum heat supply;

[0042] A determination module: for determining the start-stop plan of the cogeneration unit based on the heat supply that the cogeneration unit can provide and the obtained heat load prediction curve.

[0043] Preferably, the calculation module comprises a calculation unit, a determination unit and a making unit;

[0044] The calculation unit is used for calculating the minimum number of running units of the cogeneration unit based on the heat supply and the obtained heat load prediction curve;

[0045] The determination unit is used for comparing the current number of running units with the minimum number of running units to determine the number of units that need to be stopped or started;

[0046] The making unit is used for making the start-stop plan of the cogeneration unit based on the number of units that need to be stopped or started.

[0047] Compared with the prior art, the present application has the following beneficial effects:

[0048] The technical scheme provided by the present application comprises: when there is wind curtailment: calculating the maximum heat supply of the cogeneration unit based on the power supply power condition of the cogeneration unit; determining the heat supply that the cogeneration unit can provide based on the maximum heat supply; and determining the start-stop plan of the cogeneration unit based on the heat supply that the cogeneration unit can provide and the obtained heat load prediction curve, which is a new mode of unit combination for improving the wind power accommodation capacity, meets the actual heat and power joint dispatching demand, further improves the wind power accommodation space under the premise of guaranteeing the heat supply demand, fully utilizes the heat load prediction, and further improves the utilization rate of wind power. BRIEF DESCRIPTION OF DRAWINGS

[0049] Figure 1 The overall step flowchart of the present application;

[0050] Figure 2 The heat and power unit start-stop plan making flowchart of the present application. DETAILED DESCRIPTION

[0051] For a better understanding of the present application, the details of the application will be further described with the accompanying drawings and examples.

[0052] Example 1

[0053] The present application aims to overcome the shortcomings of the prior art and proposes a method for developing a start-stop plan of a cogeneration unit for thermal-electric combined scheduling as shown in Figure 2

[0054] The method first evaluates the maximum heat supply load within the heat supply range of the thermal power plant according to the heat load prediction data for the next week, and then determines the start-stop plan of the cogeneration unit that meets the heat supply demand based on the heat supply capacity of the cogeneration unit. The present application determines the minimum number of running units of the cogeneration unit by using the prediction of the maximum heat supply demand of the thermal power plant, which is a new mode of unit combination for improving the wind power consumption capacity, meets the actual thermal-electric combined scheduling demand, and further improves the space for wind power consumption under the premise of guaranteeing the heat supply demand.

[0055] As shown in Figure 1 , the specific steps are as follows:

[0056] Step one: when there is wind curtailment: calculate the maximum heat supply of the cogeneration unit based on the power supply power condition of the cogeneration unit;

[0057] Step two: determine the heat supply capacity provided by the cogeneration unit based on the maximum heat supply;

[0058] Step three: determine the start-stop plan of the cogeneration unit based on the heat supply capacity provided and the obtained heat load prediction curve.

[0059] The method considers the heat load prediction for the next week and develops the start mode of the cogeneration unit under the premise of guaranteeing the heat supply demand, thereby improving the utilization rate of wind power.

[0060] Among them, step one: when there is wind curtailment: calculate the maximum heat supply of the cogeneration unit based on the power supply power condition of the cogeneration unit, including:

[0061] Step 1-1: based on the start plan of the conventional generator unit for the next week, including various types of generator units such as thermal power, hydropower, nuclear power, etc., the minimum technical output of each unit is accumulated hour by hour to obtain the day-ahead minimum technical output curve of the whole network.

[0062] Step 1-2: according to the load prediction and the transaction plan of the outgoing liaison line for the next week, the total network generation load for the next week is accumulated, and the difference between the generation load and the minimum technical output is the wind power consumption space. ​

[0063] Step 1-3: Compare the wind power prediction in the next week with the wind power accommodation space, and identify the wind power prediction exceeding the wind power accommodation space as wind curtailment.

[0064] Step 1-4: Determine whether there is wind curtailment in the next week, if there is wind curtailment in the next week, execute step 1-5, if there is no wind curtailment, do not develop thermal-electric combined dispatch unit commitment, and the process ends.

[0065] Step 1-5: According to the thermal load prediction system, the thermal load prediction in the next week is evaluated, and the thermal load prediction curve H L,t in the next week is evaluated.

[0066] Step 1-6: According to the operation characteristics of the cogeneration unit of the thermal power plant, the maximum heat supply capacity of each cogeneration unit is calculated.

[0067] Cogeneration units mainly include back pressure type and extraction type, and their operation models are mainly as follows:

[0068] P b,e =c m P b,h +K b (1)

[0069] max{P c,e,min -c v2 P c,h ,c m P c,h +K c}≤P c,e ≤P c,e,max -c v1 P c,h (2)

[0070] P b,e ,P b,h ,P c,e ,P c,h are the power supply and heat supply power of back pressure type thermal power units, c m is the thermal-electric coupling coefficient in back pressure condition, c v1 ,c v2 are the thermal-electric coupling coefficients in the maximum and minimum power supply conditions of extraction type units, K b ,K c are coupling constants, and P c,e,min ,P c,e,max are the minimum and maximum power supply in condensing condition.

[0071] The power generation of the cogeneration unit runs between the minimum power supply P min and the maximum power supply P maxbetween the maximum output is generally thermal power unit installed capacity, according to formula (1) and formula (2) can be known,

[0072] The maximum heat supply value of the back pressure combined heat and power unit is P b,h,max =(P b,e,max -K b ) / (c m );

[0073] The maximum heat supply value of the extraction combined heat and power unit is P c,h,max =(P c,e,max -K c ) / (c m +c v1 );

[0074] Step two: determining the heat supply provided by the combined heat and power unit based on the maximum heat supply;

[0075] Based on the heat supply safety, the heat supply power of the combined heat and power unit considers a certain safety margin η (generally 10%-30%), and the heat supply power of the combined heat and power unit meeting the certain heat supply safety margin needs to meet the following formula:

[0076]

[0077] In the formula, P 可 is the heat supply provided by the combined heat and power unit; P h,i,t is the heat supply of each combined heat and power unit at the same time according to the heat load prediction curve.

[0078] Step three: determining the start-stop plan of the combined heat and power unit based on the provided heat supply and the obtained heat load prediction curve, including:

[0079] Step 3-1: combining the maximum heat supply capacity of the combined heat and power unit and the heat supply safety margin, calculating the minimum number of running combined heat and power units meeting the heat load demand in the future week according to the following formula:

[0080]

[0081] Step 3-2: according to the running state of the combined heat and power unit of the current thermal power plant, determining whether the number of running combined heat and power units is greater than the minimum number of running units, if the number of running combined heat and power units is greater than the minimum number of running units, giving the suggestion of the number of stopped units; if the number of running combined heat and power units is less than the minimum number of running units, giving the suggestion of starting; if the number of running combined heat and power units is equal to the minimum number of running units, keeping the original unit operation plan unchanged;

[0082] Step 3-3: Based on the start-stop machine suggestion of the cogeneration unit of the thermal power plant, it is judged whether the maximum / minimum output of the thermal power unit after the start / stop of the cogeneration unit meets the load demand. If yes, the start-stop machine plan of the thermal power plant is executed. If no, the adjustment suggestion of the start-stop machine plan of the thermal power plant is given.

[0083] Step 3-4: Based on the result of step 3-3, the start-stop machine plan of the cogeneration unit of the thermal power plant is made and is sent to the thermal power plant for execution.

[0084] Embodiment 2

[0085] Based on the unified inventive concept, the application further provides a start-stop machine plan making system of a cogeneration unit, which comprises:

[0086] The first calculation module is used for, when there is abandoned wind, calculating the maximum heat supply of the cogeneration unit based on the power supply condition of the cogeneration unit.

[0087] The second calculation module is used for determining the heat supply that can be provided by the cogeneration unit based on the maximum heat supply.

[0088] The determination module is used for determining the start-stop plan of the cogeneration unit based on the heat supply that can be provided and the obtained heat load prediction curve.

[0089] The calculation module comprises a calculation unit, a determination unit and a making unit.

[0090] The calculation unit is used for calculating the minimum running number of the cogeneration unit based on the heat supply and the obtained heat load prediction curve.

[0091] The determination unit is used for comparing the current running number with the minimum running number to determine the number of the units that need to be stopped or started.

[0092] The making unit is used for making the start-stop plan of the cogeneration unit based on the number of the units that need to be stopped or started.

[0093] Those skilled in the art should understand that the embodiments of the application can be provided as a method, a system or a computer program product. Therefore, the application can be in the form of a complete hardware embodiment, a complete software embodiment or an embodiment combining software and hardware aspects. Moreover, the application can be in the form of a computer program product implemented on one or more computer usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer usable program code.

[0094] The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 one or more flowcharts and / or blocks. Figure 1 one or more flowcharts and / or blocks.

[0095] These computer program instructions can also be stored in a computer readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture including instructions which implement the function specified in the flowchart block or blocks. Figure 1 one or more flowcharts and / or blocks. Figure 1 one or more flowcharts and / or blocks.

[0096] The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 one or more flowcharts and / or blocks. Figure 1 one or more flowcharts and / or blocks.

[0097] The above merely provides an embodiment of the present application, but is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall fall within the scope of the claims of the present application.

Claims

1. A method for developing a start-stop schedule of a cogeneration unit, characterized by, The method comprises: when there is curtailment of wind power, calculating a maximum heat supply of a cogeneration unit based on a power supply condition of the cogeneration unit; determining a heat supply capacity of the cogeneration unit based on the maximum heat supply; determining a start-stop plan of the cogeneration unit based on the heat supply capacity and an obtained heat load prediction curve; the determining of the start-stop plan of the cogeneration unit based on the heat supply capacity and the obtained heat load prediction curve comprises: calculating a minimum number of running units of the cogeneration unit based on the heat supply capacity and the obtained heat load prediction curve; comparing the current number of running units with the minimum number of running units to determine a number of units that need to be stopped or started; formulating the start-stop plan of the cogeneration unit based on the number of units that need to be stopped or started; the calculation formula of the minimum number of running units is as follows: In the formula, I is the number of operation of the cogeneration unit; η is the safety margin; P h,i,max is the maximum heat supply of each cogeneration unit; P c,e,max is the maximum power supply of the cogeneration unit in the condensing condition; K b ,K c is the coupling constant; c m is the heat and power coupling coefficient of the back pressure condition; c v1 is the heat and power coupling coefficient of the maximum power supply condition of the extraction turbine unit; H L,t is the heat load prediction curve; I b is the number of operation of the back pressure cogeneration unit; I c is the number of operation of the extraction turbine cogeneration unit.

2. The method of claim 1, wherein, the determining of the heat supply capacity of the cogeneration unit based on the maximum heat supply comprises: determining a range of safety margin according to the power of the cogeneration unit; determining a range of heat supply capacity of the cogeneration unit according to the range of safety margin and the maximum heat supply; wherein the safety margin is 10%-30%.

3. The method of claim 2, wherein, the calculation formula of the heat supply capacity of the cogeneration unit is as follows: In the formula, P 可 is the heat supply available for the cogeneration unit; P h,i,max is the maximum heat supply of each cogeneration unit; H L,t is the heat load prediction curve; and η is the safety margin.

4. The method of claim 1, wherein, the calculation formula of the maximum heat supply of the cogeneration unit is as follows: P b,h,max = (P b,e,max - K b ) / c m P c,h,max = (P c,e,max - K c ) / (c m + c v1 ) wherein P b,h,max is the maximum heat supply of the back pressure combined heat and power unit; P b,e,max is the maximum power supply of the back pressure combined heat and power unit; P c,h,max is the maximum heat supply of the extraction combined heat and power unit; P c,e,max is the maximum power supply of the condensing combined heat and power unit; K b ,K c is the coupling constant; c m is the heat and power coupling coefficient of the back pressure combined heat and power unit; c v1 is the heat and power coupling coefficient of the extraction combined heat and power unit.

5. The method of claim 1, wherein, the formulating of the start-stop plan of the cogeneration unit further comprises: if the start-stop plan meets the heat supply demand, the start-stop plan is sent to the cogeneration plant for execution; otherwise, the curtailment of wind power is recalculated, the maximum heat supply of the cogeneration unit is calculated based on the power supply condition of the cogeneration unit, the heat supply capacity of the cogeneration unit is determined based on the maximum heat supply, the start-stop plan of the cogeneration unit is determined based on the heat supply capacity and the obtained heat load prediction curve, and the start-stop plan that meets the heat supply demand is sent to the cogeneration plant for execution. until the start-stop plan that meets the heat supply demand is obtained and sent to the cogeneration plant for execution. the calculation of the curtailment of wind power comprises: obtaining a heat load prediction curve and a wind power; 6. The method of claim 1, wherein, obtaining a minimum technical output of the whole network based on a start plan of a conventional generator unit; obtaining a predicted generation load of the whole network in a prediction time period based on the heat load prediction curve and a transaction of an external sending tie line; calculating a difference between the predicted generation load of the whole network and the minimum technical output of the whole network to obtain a wind power accommodation space; calculating the curtailment of wind power based on the wind power and the wind power accommodation space. The system comprises: a first calculation module configured to, when there is curtailment of wind power, calculate a maximum heat supply of a cogeneration unit based on a power supply condition of the cogeneration unit; 7. A start-up and shutdown planning system for a combined heat and power (CHP) unit, characterized in that, a second calculation module configured to determine a heat supply capacity of the cogeneration unit based on the maximum heat supply; a determination module configured to determine a start-stop plan of the cogeneration unit based on the heat supply capacity and an obtained heat load prediction curve; the calculation module comprises a calculation unit, a determination unit and a formulating unit; the calculation unit is configured to calculate a minimum number of running units of the cogeneration unit based on the heat supply capacity and the obtained heat load prediction curve; the determination unit is configured to compare the current number of running units with the minimum number of running units to determine a number of units that need to be stopped or started; and the formulating unit is configured to formulate the start-stop plan of the cogeneration unit based on the number of units that need to be stopped or started. ​ The planning unit is configured to plan a start-stop plan of the combined heat and power unit based on the number of units that need to be stopped or started. The calculation formula of the minimum number of units in operation is as follows: In the formula, I is the number of operation of the combined heat and power unit; η is the safety margin; P h,i,max is the maximum heat supply of each combined heat and power unit; P c,e,max is the maximum power supply of the combined heat and power unit in the condensing condition; K b ,K c is the coupling constant; c m is the combined heat and power coupling coefficient in the back pressure condition; c v1 is the combined heat and power coupling coefficient in the maximum power supply condition of the extraction turbine unit; H L,t is the heat load prediction curve; I b is the number of operation of the back pressure combined heat and power unit; I c is the number of operation of the extraction turbine combined heat and power unit.

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